Filter-pulp-washing machine.



K. KIEFER. FILTER PULP WASHING MACHINE. APPLICATION FILED FEB. 25, 1907.

Patented Aug. 20, 1912.

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' KARL KIEFEB, OF CDTCINNATI, OHIO.

' FILTEB-PULP-WASBING MACHHW E.

Specification of Letters Patent.

Patented Aug. 20,1912.

Application tiled February 25, 1907. Serial No. 859,080.

Machines, of which the following is a 'speci-- fication.

The object of my invention is to wash filter pulp that has beencontaminated by the process of filtration with impurities,

such as yeast cells and other suspended matter; to bring pulp afterbeing cleansed to a flocculent and silky condition, and at the same timeto prevent the formation of balls or knots in the pulp. The object isattained by means of novel means and arrangements in the construction asset forth in this specification and illustrated in the accompanyingdrawings, of which Figure 1 is a cross section through the center of themachine and Fig. 2 a detail view upon the center part of the machine.

The apparatus consists of a large tank A having av funnel shaped part tofacilitate the drawing off of the cleansed filter pulp from the outlet2. This tank is carried on frame work B. Cent-rally revoluble within thetank is the. conveyer screw C fastened to shaft 3 and set in motion byright angle belt drive D by means of pulley 4., Shaft 3 revolves instufiing box 5 and is supported in foot bearing 6. steadies the shaftat'its extreme upper end. Centrally within the main tank A is a secondcylinder E and a screen cylinder F.

Between cylinders E and F is a ring shaped space which is closed towardthe bottom by ring 8 and toward the top by ring 9 so that no filter pulpcan enter the ring-shaped space between E and F, butthe water canpercolate through the screen cylinder from the center of the washingmachine to the ring shaped space mentioned. From there it finds an exitthrough tube 10 and the gooseneck overflow 11. Ring 9 is held by rods 12centrally and down against the cylinder E, which in turn is held againstthe ring 8, which ring is supported by feet 13 so as to carry thecylinders E and F centrally within the .tank A and'allow free cir- F isby means of the cast iron ring 1Q so Another bearing 7 ig. 1. Theprefer-- that it can be pulled out of the ring 9, which facilitates athorough cleaning of the screen from its reverse side. 'During theoperation of washing, it may be held down by screws 15 against ring 9,but its own weight may be sufiicient. The bearing 7 is centered by meansof the thin bolts 16, Fig. 2, which are taken of small cross sections soas not to obstruct the flow'of pulp.

The operation of the machine is simple. The screw C.rotates at a highspeed,-which is about 250 revolutions when the screw is about 12 inchesin diameter and for a 1,000 gallon tank. This action of the screw causesthe pulp to ascend rapidly within the cylinder F and a circulation asshown by the arrows is readily obtained. The screw C also communicates acentrifugal motion to the pulp and water mixture and the water being ofa higher specific gravity than the pulp, is pressed into the annularspace between cylinders E and F and issues at the gooseneck 11. Thiswater contains the impurities, While the pulp itself is retained in thevessel I by the screen F and passed upward to mix with fresh water. Thisscreen cylinder F preferably consists of an outer perforated sheet metalcylinder 17 and an interior fine mesh woven screen cylinder 18. The finemeshv cylinder 18 may contain about 40 meshes to the inch. Now,heretofore, in washing machines there was great difiiculty in keepingthe screen from being clogged by pulp, as such machines should of courseWork as rapidly as possible, and the pulp, naturally following thedirection of the water would adhere to the fine meshes of the screen andthus prevented the eflicient working. This difiiculty is avoided in myimproved Washing machine, as the current in an upward direction causedby the screw C- is so strong that such pulp, if it would attempt toformmats against the interior of the cylinder F would be broken awayimmediately, and therefore my arrangement is practically self-cleaning.The centrifugal force also tends to separate the dirty water from thepulp by virtue of thegreater specific gravity of the water, as comparedto the pulp, thus imparting to the water a gre'ater tendency to passthrough the screens than is possessedby the pulp, not onl due tothefluidity of the water, but to such greater momentum as it derivesfrom the centrifugal action. Presumably, due to this Centrifugal force,together with the head of water in the tank, the machine, in practice,produces a greater rate of out-flow than is desirable consistent withpractical economy of water, and than is necessary to properly wash thepulp and requires some means of moderating it. At the'same time, itdesirable to have the outlet from the annular space around the screencylinder near the bottom of the space, to insure proper drainage andfreedom from sediment therein. These two conditions are fulfilled byproviding the gooseneck 11, with its height'slightly below the level ofthe water in the tank, thus afl'ording a counteracting head of water inthe outlet,

only slightly less than that of the water in the tank. By regulating theheight of the gooseneck, when the machine is constructed, the combinedeffects of the head of water in the tank, and of the centrifugal forceof the screw, may be counteracted and regulated to secure the desiredrate of application of water to the pulp, in a simple, yet'eflectivemanner. If the tank be six feet in diameter, a screw one foot indiameter is suflicient to produce the desired effects, as beforedescribed, when running at the rate of about 250 revolutions erminute.To properly counteract the e ect of the screw, in the manner abovereferred to, the 'gooseneck should be from six to eight inches below thelevel of the contents of the tank, under the conditions above described.

In order to supply the fresh water, av

water connection 19 is attached to the tank,

and is provided with a valve having a float- 20, supported directly onthe surface of the mixture of pulp and water in the'tank, to keep thelevel of the water in the tank regulated to a steady height. Aperforated head 21 distributes the water uniformly over the surface ofthe mixture. A peculiarity of my machine is the large capacity providedfor water, compared to the amount of pulp to be operated upon. Forinstance, in practice, a tank with a capacity of 1,000 gallons is usedfor operating upon 135 pounds of pulp, giving it a fluid consistencespecially favorable to the operation of t e floatvalve directly on thesurface of the mixture. In this way only, can such a device be dependedupon to supply no'more water than is needed merely to supply thedeficiency. Both pzpvisions are highly important; the 'one ause theproper wor of the machine requires that a certain fluidity of contentsbe maintained, and the other, because the necessaril variableconductivity of the screen 0 der results in running over of the contentswith the use of any'contro meansfnot operated by direct contact theitself. a

The cylinders E and F are connected to the bottom" shell of the tank,which is preferable, because the bottom shell, being cone-shaped, isstiffer than the sides.

What I claim as my invention and desire to secure by Letters Patentis 1. In a filter pulp washing machine, a tank holdin a mixture of pulpand water, an outlet om the tank through which water is impelled toseparate it from the pulp, means for impelling the water, a water inletto the tank, a valve in said inlet, and afloat directly on the surfaceof said mixture in the tank, to control said valve.

2. In a filter pulp washing machine, a

tank holding a mixture of pulp and water,

an outlet from the tank through which water is impelled to separate itfrom the pulp, means for impelling'the water, said outlet and saidimpelling means being submerged in said mixture, and the outlet hav-ving an opening, outside the tank, above the highest level at which theimpelling means operates, but below the level of the surface of themixture.

3. In a filter pulp washing machine, the combination of an exterior tankand an interior cylindrical and stationary screen, of a cylindersurrounding said screen surface so as to produce an inclosed space,means for conducting liquid within said inclosed space through said tankand below the liquid level, and agitating means surrounded by saidscreen. A

4. In a filter pulp washing machine the combination of an exterior tank,a central cylindrical screen surface, of an agitating screw within saidscreen cylinder, means to produce an inclosed space on the outside of 7said screen cylinder, and means to conduct the water entering saidinclosed space out side of said tank. I

5. In a filter pulp washing machine, a tank holding a mixture of pulpand water, a conduit with pervious walls submerged in said mixture,means inclosing an outlet space around the pervious walls of theconduit, said means and said pervious walls excluding pulp from saidoutlet space but said pervious walls admitting water there- .to, meanscontained in said conduit to impel the water throu h said perviouswalls, and an outlet from tie lower region of said outlet space, openingoutside the tank and above the highest level at which the impellingmeans operates, but below the level of the mixture in the tank.

6. In a filter pulp washing machine, a tank hol a mixture of pulp andwater, an outlet cm the tank through which water is impelled to separateit from the pul means forimpelling said water, said on at and saidimpelling "means being submerged in said mixture, and the outlet havmgopening, outside the tank, above the highest level at which theimpelling means of the mixture, means for supplying water to the mixturein the tank, and means for regulating the supply of water automatically.

7. In a filter pulp washin machine, a tank holding a mixture of pu p andwater,

outlet means from the tank having a stationary pervious wall admittingwater to the outlet but excluding pulp therefrom, and means to impelWater through said pervious wall, moving in close proximity to said wallto clean the wall of accumulated pulp, but out of contact therewith,whereby it avoids balling and knotting of the fiber of the pulp.

8. In a filter pulp washin machine, a tank holding a mixture of pu p andwater, an interior upright conduit with pervious walls and open at itslower and its upper ends to admit circulation of the mixturecontinuously upward through it, means in said conduit agitating themixture and propelling it upward through the conduit, and also actingcentrifugall on the mixture, said pervious walls al owing passage ofwater but preventing the passage of pulp, and the centrifugal action onthe mixture impelling the water through said pervious walls to separateit from the pulp, and means for conducting the water away from saidpervious walls, with the pulp excluded, to the exterior of the tank.

9. In a filter pulp washing machine, a tank holding a mixture of pulpand water, an interior upright conduit with pervious walls and open atits lower and its upper ends to admit circulation of the mixturecontinuously upward through it, means in said conduit agitating themixture and propelling it upward through the conduit, said means alsoacting centrifugally on the mixture, said pervious walls allowing thepassage of water and sediment but preventing the passage of pulp, andthe centrifugal action on the mixture being to impel the water andsediment through said pervious walls to separate said water and sedimentfrom the pulp, and means, leading from said pervious walls, in the lowerregion of said conduit, for conducting water and sediment away from saidpervious walls, with the pulp excluded, to the exterior of the tank.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

KARL KIEFER.

Witnesses G. W. WERDEN, SAML. J. WEIS.

